Feline Calicivirus: one of the three most common diseases in cats
Aug 20, 2021
1. What is Feline Calicivirus (FCV)?
Feline Calicivirus(FCV) is a virus that causes upper respiratory tract infection (URI) in cats. Feline Calicivirus(FCV) is a highly contagious virus that can cause mild to severe respiratory infections and oral diseases in cats. It is particularly common in shelters and breeding grounds, and it often infects kittens. Most cats recover completely after being infected with calicivirus, but rare strains of the virus are particularly deadly. This virus poses no threat to humans. Feline Calicivirus (FCV) belongs to a large family called Caliciviridae , and its members infect a variety of vertebrates, including rabbits, livestock, reptiles, birds, and amphibians. The human virus, norvirus, is a member of the Caliciviridae family and can cause transient but unpleasant gastrointestinal diseases.
Several types of FCV spread among domestic cats and wild cats. This virus is prone to mutation, resulting in new strains that may not be fully covered by existing vaccines. Strains vary in the severity of the diseases they cause, and most cause only mild diseases . The mutation ability of this virus may explain why outbreaks still occur frequently after 40 years of FCV vaccination.
2.Why is my cat infected?
FCV is most common in multi-cat environments. Cats are in shelters, pet shops, and places where the risk of exposure is higher, where 25% to 40% of cats may be carriers.
The virus is spread through direct contact with the saliva, nasal mucus, and eye secretions of an infected cat, as well as aerosol droplets transmitted when the cat sneezes. Laboratory tests also found the virus in urine, feces and blood. Cats usually spread the virus within two to three weeks after being infected with the virus, but some cats will become long-term carriers and spread the virus intermittently for several months.
FCV is a very vigorous virus that can survive on the surface for up to a month in certain environments. People who come into contact with infected cats may inadvertently transmit the virus to new animals. Objects that come into contact with the cat's body fluids, such as food bowls, litter boxes, or cat bedding, may also be the source of infection.
3. What about during the infection?
After exposure to FCV, the incubation period is 2 to 14 days before symptoms appear. This virus may initially infect the lining of the back of the mouth. After the virus replicates there, it may spread to other organs through the blood. However, FCV preferentially infects the oral cavity and lung tissues. Most cats will develop upper respiratory tract infections, and in more severe cases, the virus can enter the lungs and cause pneumonia.
The symptoms of a cat depend on the severity of the FCV it is infected with.
At first, the cat will show cold-like symptoms, including sneezing, nasal congestion, fever, and sometimes drooling. A large amount of discharge may come from the eyes and nose. In more severe cases, cats will also develop inflammation and ulcers on the lining of the tongue and mouth. Drowsiness, mild claudication, and loss of appetite may also occur.
Cats with runny nose and large eye discharge These symptoms can last for 5 to 10 days in mild cases and 6 weeks in severe cases. In the course of illness, sometimes bacterial infections may also occur. Cats may lose weight, and infections may also cause miscarriages in pregnant cats. Most cats recover completely, but some will develop chronic gingivitis, which can cause thick and inflamed gums and painful eating. Older cats and kittens are more likely to have more severe symptoms.
Calicivirus causes mouth ulcers
Fortunately, cats rarely die from FCV infection. Cats that develop FCV-VSD will have more severe symptoms:
These include high fever, swelling of the head and legs, as well as crusted ulcers and hair loss on the nose, eyes, ears, and foot pads.
The mouth and ears may turn yellow due to liver damage, and bleeding may occur under the skin and digestive tract.
FCV-VSD is fatal in up to 60% of cats.
4. How to diagnose calicivirus?
In most cases, the presumptive diagnosis of calicivirus infection is based on typical clinical symptoms, especially ulcers. A definitive diagnosis of the virus is not always necessary, but it may be recommended for raising animals, or if a cat is infected with the virus and does not respond well to treatment.
Diagnosis can be done by collecting cell samples and secretions from the mouth, nose, or eyes, and submitting these samples to a laboratory for special testing. The FCV antigen test kit provided by Aijin Biotech also uses the secretions of the mouth, nose, and anus for testing, which can quickly determine whether a cat is infected or not within 5-10 minutes.
If the infection has spread to the lungs, a sample can be collected for testing through a procedure called transtracheal irrigation. If a cat suddenly shows signs of limp, x-rays may be recommended to rule out other causes, such as injuries. If the cat has persistent respiratory symptoms, your veterinarian will recommend additional diagnostic tests, such as chest or skull x-rays, blood tests, or culture and sensitivity tests for abnormal discharge.
Commercial laboratories use two methods to detect the presence of FCV: one is to culture the virus in a petri dish, and the other is to use reverse transcriptase PCR (RT-PCR), which can detect a portion of calicivirus-specific genetic material. Although RT-PCR testing may be more common in some regions, the effects of the two testing methods are the same
5. What is the treatment for calicivirus in cats?
There is currently no treatment to stop this virus, but pet owners can provide supportive care for their cats, and the cat's immune system can fight the infection. Most cats can recover at home, but severely infected cats may require intensive care.
Keep the cat's nose and eyes clean, and use a sprayer and saline nasal drops to help clear the nasal passages. A drug that breaks down mucus, such as bromopurine, can also help relieve congestion. Non-steroidal anti-inflammatory drugs can reduce fever and relieve oral pain. If necessary, broad-spectrum antibiotics can be used to treat opportunistic bacterial infections.
Cats often lose their appetite due to oral congestion and ulcers and stop eating. Feeders should provide soft foods with strong odors. These foods can be made into puree to make them easier to swallow, and heated slightly to increase their odor. If cats have not eaten for more than three days, they may need to be hospitalized for fluids and intravenous nutrition
If your cat has purulent (green/yellow) eye discharge, your veterinarian may prescribe you a topical ophthalmic medication. Although viral infections do not respond to antibacterial drugs, doctors may prescribe broad-spectrum antibacterial drugs (such as amoxicillin-clavulanic acid combinations) to prevent secondary bacterial infections from complicating the disease, especially in kittens.
Cats with nasal congestion or airway obstruction may benefit from environmental humidification, such as being taken into a humid bathroom several times a day for 10-15 minutes. In order to minimize the irritation of the secretions, it is helpful to wipe the secretions from the cat's face or eyes with a moist tissue. Since cats with respiratory infections have a weakened sense of smell, their appetite will also decrease. Eating some slightly heated, delicious canned food may help improve their appetite. In some cases, the doctor may prescribe an appetizer for you.
If a cat has FCV-VSD, it should receive intensive care, including intravenous fluids, antibiotics, and other treatments as needed.
6. How to prevent calicivirus?
Vaccines cannot completely prevent FCV, but if your cat is exposed to vaccines, they can greatly reduce the severity of the infection. There are currently several combined vaccines against FCV, Feline Herpesvirus Type 1 and Feline Panleukopenia Virus (the cause of cat and canine distemper ), which can be injected intranasally or injected. The vaccinated vaccine contains a modified live virus, and the injected vaccine can be a modified live virus or an inactivated virus. Cats receiving the nasal vaccine may sneeze for 4 to 7 days after being vaccinated.
Cat triple vaccine
The Association of Practitioners (AAFP) recommends that kittens be vaccinated with core vaccines (FPV, FHV, FCV) at 6-8 weeks of age, and then vaccinated again every 3-4 weeks until they are 16 weeks of age. Adult vaccines are given at 1 year old and then every 3 years. Your veterinarian may recommend a revised schedule based on your cat's exposure risk and potential health problems. The rabies vaccination schedule is slightly different because it occurs once at 3 months of age, then once at 1 year of age, and then once every 3 years. If cats are in a high-risk, multi-cat environment, in this case, they should be revaccinated every year. Even cats infected with calicivirus should receive boosters because they may not be able to resist other strains of the virus.
Studies have shown that vaccines can prevent viruses faster.
There is currently a vaccine called Calicivax, which includes an improved form of the FCV strain that causes FCV-VSD, and a typical FCV strain. The vaccine may have a certain protective effect on FCV-VSD outbreaks, but because the virulent strains that cause These outbreaks are derived from different mutations in low-invasive strains, it is unclear how effective Calicivax is against future outbreaks. Calicivax is not part of the core vaccine recommended for all cats.
If you have multiple cats and one or more of them are receiving FCV treatment, then you should isolate the infected animals, clean food and water bowls, litter boxes and other items that may be contaminated by the virus. The diluted bleach solution, containing half a cup of bleach per gallon of water, can effectively kill the virus. Cleansing solutions that contain phenols, such as Lyso water, are also effective, but they should not be used on cats because they can irritate cats and are toxic. During this time , the owner may wish to take other cats away from the house to prevent contact. The virus will die naturally after a month.
Cats that become carriers of the virus will continue to spread the virus at home, even if they have recovered from the infection. The owner needs to bring the virus-carrying cat home again, and then disinfect it to protect the remaining animals from infection.
When you bring a new cat to the house, it is wise to isolate it from other cats in the house for one to two weeks and watch for signs of illness.
Regarding the FCV disease, the shit scavengers must not think that everything will be fine if the vaccine is given, because the protection period of the vaccine is also limited, so it is very necessary to get the vaccine regularly. The vaccine is only tens of hundreds of dollars, but it saves money for the vaccine. As long as the cat gets sick, it will cost far more than tens of hundreds of dollars, and it will be carried for life, which is very worrying.
